Field of the Disclosure
This disclosure relates to a slotted waveguide antenna, in particular to a slotted waveguide antenna with metamaterial structures.
Description of Related Art
Generally, slotted waveguide antennas (SWAs) include a rectangular waveguide with slots formed in at least one surface. Electromagnetic energy may be provided to the SWA by a transmission line and/or another waveguide configured to couple a transmitter and/or receiver to the SWA. For example, SWAs may be used in navigational radar applications. SWAs may be configured to operate at one or more frequencies between about 1 gigahertz (GHz) and about 26 GHz.
SWA antenna characteristics, including gain and directivity, are related to a physical size of the SWA. In order to increase gain and/or directivity, the size of the SWA may be increased. Increasing size may result in increased weight and/or mechanical instability. SWA antenna characteristics may be improved without increasing size by adding dielectric material inside the waveguide. Dielectric materials can be lossy (i.e., non-zero loss tangent) and, thus, may detrimentally affect the gain of the SWA.